PURPOSE: One copy of the galanin receptor 1 (GALR1) locus on 18q is often deleted and expression is absent in some head and neck squamous cell carcinoma (HNSCC) cell lines. To determine if loss of heterozygosity and hypermethylation might silence the GALR1 gene, promoter methylation status and gene expression were assessed in a large panel of HNSCC cell lines and tumors. EXPERIMENTAL DESIGN: Promoter methylation of GALR1 in 72 cell lines and 100 primary tumor samples was analyzed using methylation-specific PCR. GALR1 expression and methylation status were analyzed further by real-time PCR and bisulfite sequencing analysis. RESULTS: The GALR1 promoter was fully or partially methylated in 38 of 72 (52.7%) HNSCC cell lines but not in the majority 18 of 20 (90.0%) of nonmalignant lines. GALR1 methylation was also found in 38 of 100 (38%) primary tumor specimens. Methylation correlated with decreased GALR1 expression. In tumors, methylation was significantly correlated with increased tumor size (P = 0.0036), lymph node status (P = 0.0414), tumor stage (P = 0.0037), cyclin D1 expression (P = 0.0420), and p16 methylation (P = 0.0494) and survival (P = 0.045). Bisulfite sequencing of 36 CpG sites upstream of the transcription start site revealed that CpG methylation within transcription factor binding sites correlated with complete suppression of GALR1 mRNA. Treatment with trichostatin A and 5-azacytidine restored GALR1 expression. In UM-SCC-23 cells that have total silencing of GALR1, exogenous GALR1 expression and stimulation with galanin suppressed cell proliferation. CONCLUSIONS: Frequent promoter hypermethylation, gene silencing, association with prognosis, and growth suppression after reexpression support the hypothesis that GALR1 is a tumor suppressor gene in HNSCC.
PURPOSE: One copy of the galanin receptor 1 (GALR1) locus on 18q is often deleted and expression is absent in some head and neck squamous cell carcinoma (HNSCC) cell lines. To determine if loss of heterozygosity and hypermethylation might silence the GALR1 gene, promoter methylation status and gene expression were assessed in a large panel of HNSCC cell lines and tumors. EXPERIMENTAL DESIGN: Promoter methylation of GALR1 in 72 cell lines and 100 primary tumor samples was analyzed using methylation-specific PCR. GALR1 expression and methylation status were analyzed further by real-time PCR and bisulfite sequencing analysis. RESULTS: The GALR1 promoter was fully or partially methylated in 38 of 72 (52.7%) HNSCC cell lines but not in the majority 18 of 20 (90.0%) of nonmalignant lines. GALR1 methylation was also found in 38 of 100 (38%) primary tumor specimens. Methylation correlated with decreased GALR1 expression. In tumors, methylation was significantly correlated with increased tumor size (P = 0.0036), lymph node status (P = 0.0414), tumor stage (P = 0.0037), cyclin D1 expression (P = 0.0420), and p16 methylation (P = 0.0494) and survival (P = 0.045). Bisulfite sequencing of 36 CpG sites upstream of the transcription start site revealed that CpG methylation within transcription factor binding sites correlated with complete suppression of GALR1 mRNA. Treatment with trichostatin A and 5-azacytidine restored GALR1 expression. In UM-SCC-23 cells that have total silencing of GALR1, exogenous GALR1 expression and stimulation with galanin suppressed cell proliferation. CONCLUSIONS: Frequent promoter hypermethylation, gene silencing, association with prognosis, and growth suppression after reexpression support the hypothesis that GALR1 is a tumor suppressor gene in HNSCC.
Authors: Roberto Lin; Yoshihiko Nagai; Robert Sladek; Yolande Bastien; Joanne Ho; Kevin Petrecca; Georgia Sotiropoulou; Eleftherios P Diamandis; Thomas J Hudson; John H White Journal: Mol Endocrinol Date: 2002-06
Authors: Tamotsu Kuroki; Francesco Trapasso; Sai Yendamuri; Ayumi Matsuyama; Hansjuerg Alder; Masaki Mori; Carlo M Croce Journal: Cancer Res Date: 2003-07-01 Impact factor: 12.701
Authors: Shinichi Toyooka; Kiyomi O Toyooka; Kenichi Harada; Kuniharu Miyajima; Prakash Makarla; Ubaradka G Sathyanarayana; Jing Yin; Fumiaki Sato; Narayan Shivapurkar; Stephen J Meltzer; Adi F Gazdar Journal: Cancer Res Date: 2002-06-15 Impact factor: 12.701
Authors: Rajat Banerjee; Elizabeth A Van Tubergen; Christina S Scanlon; Robert Vander Broek; Joel P Lints; Min Liu; Nickole Russo; Ronald C Inglehart; Yugang Wang; Peter J Polverini; Keith L Kirkwood; Nisha J D'Silva Journal: Mol Cancer Ther Date: 2014-02-25 Impact factor: 6.261
Authors: Graham M Poage; Rondi A Butler; E Andrés Houseman; Michael D McClean; Heather H Nelson; Brock C Christensen; Carmen J Marsit; Karl T Kelsey Journal: Cancer Res Date: 2012-04-16 Impact factor: 12.701
Authors: Jorge L Sepulveda; Jorge L Gutierrez-Pajares; Aesis Luna; Yuan Yao; John W Tobias; Steven Thomas; Yanghee Woo; Federico Giorgi; Elena V Komissarova; Andrea Califano; Timothy C Wang; Antonia R Sepulveda Journal: Mod Pathol Date: 2016-01-15 Impact factor: 7.842